After a search for my issue and was not really able to find anything that would help me so I thought I would just go ahead and ask.

Working on my 99 Dakota with 5.2 today, changed spark plugs and wires I noticed that my Plenum, (think its called that) has an open vacum port on the passengers side. There are two ports or inlets on this side actually, one is hooked up the PCV into the top of the valve covers right? The other one is just open and DOES have a vacuum. I know this because I put my finger over it while the engine was running.

When I covered it the engine would actually slow a little in idle.

I was thinking since its just open something should be hooked up it right? or can I just plug it with something.

If I plug it, what to I use to accomplish this?

Thanks for replies

 

there are two of them inlets as you call them one on both sides there should actually be 4 to large and two small. there are suppost to be little caps over the the smaller ones. there in the intake for doing vacume tests and hooking up a gauge and other testing equipment at the dealer. also for options that may need vacume to control them.

 

Had the same thing on my dakota, to answer your question those vacuum ports should be caped off with a little rubber cap, as atthewmartin144 said, I would highly recommend you find something to plug those up ASAP. Leaving those open allows dust and debris to enter your intake. When you do plug them reset your computer by cycling your key on/off 5 times, thus allowing your truck to run right, otherwise when you start you truck up it will have a hard time idling and may die.

 

Yup, it needs to be capped. My friends 5.2 was missing one of those caps and the truck would idle like crap. Went to advanced and picked up some caps in an assorted pack and found one that fit. Now the engine idles smooth and at a low rpm.